Electric pulsator for milking machines



June13, 1933. Q H HAPGOD 1,914,122

ELECTRIC PULSATCR FOR MILKING MACHINES Filed J'ly 1l, 1931 /V/f/VESS: @rus Patented June 13, 1933 UNITED STATES PATENT OFFICE CYR'US HOWARD HAPGOOD, OF NUTLEY, NEW JERSEY, ASSIGNOR TO THE DE LAVAL j SEPARATOR COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY ELECTRIC PULSATOR FOR- MILKING lVIACl-IINES Application. filed July 11,

The-obj ect of the invention is to provide an electric circuit make and break device adapted to be actuated by a vacuum pump and which is capable of ready adjustment to predetermine the make and break intervals.

The vacuum pump which I utilize to operate the make and break device is of the type disclosed in the Leitch Patent No. 1,367,- 554, dated February 8, 1921, the Hall Patent No. 1,374,650, dated April 12, 1921, and patents issued to me, No. 1,637,484, dated August 2, 1927, and No. 1,684,395, dated September' 18, 1928.

In the drawing, which shows a preferred embodiment of the invention: Fig. l is a longitudinal section through the pump. Fig. 2 is a section on the line 2 2 of Fig. 1.

Rotor a is splined on a shaft c extending through a housing b. The rotor has slots through which wings or vanes extend into the air compression space between rotor and housing and into contact with the inner circumferential wall of the housing, these vanes sliding toward and from the shaft in the rotation of the rotor, which is eccentrica-ily disposed with relation to the housing. Keyed to the shaft c is a driving pulley d.

The shaft turns in bearings carried by the housing. The bearing e at the end of the shaft opposite its driven end may be of any ordinary type. The bearing at the other or driven end of the shaft may be of any suitable type. It is shown as a comparatively long bearing sleeve f extending into the interior of the rotor and through the end of a channel communicating with the discharge of the pump and also through a space communicating with a low vacuum chamber. Beyond bearing sleeve f, and between it and the driving pulley is a ball bearing g. The space occupied by ball bearing g is closed by a plate j.

Bearing sleeve f has a hole or holes h communicating with the pump discharge. It is also provided with an internal groove which communicates through a hole or holes z' with chamber c. This chamber communicates, through an opening m, with that part of the air compression space of the pump wherein the absolute pressure is between the prf ssure 1931. Serial No. 550,073.

(normally atmospheric) at the discharge of the pump and the pressure (usually about half atmospheric) at the intake of the pump. It is preferred to so locate opening m as to maintain in chamber 7c a vacuum of about two or three inches.

The various channelsfor receiving, compressing and discharging air, and the means for lubrication, including means for circulating the oil, are not herein described and form no part of the present invention, Such details are, however, fully described and shown in certain of the patents and applications hereinbefore mentioned. No oil between the shaft c and bearing sleeve f can escape endwise beyond the housing due to the sub-atmospheric pressure in chamber lc.

The described pump is primarily intended and adapted to operate a suction-operable milking machine unit (not shown), wherein pneumatic pulsations are produced by means of a valve whose operation is controlled by an electro-magnet which is intermittently actuated. This intermittent flow of electric current to the magnet is effected by a make and break device, usually called an electric pulsator, which is operable from the pump.

The cover 10 of the pump housing carries a binding post 11, to which is secured an electric conductor 12. To the same binding post is secured one end of an electric conductor 13 whose other end is secured between nuts 14 carried by a threaded rod on the end of a condenser 15. Une of the nuts 14 contacts with an angle plate 16 insulated from the condenser. Extending under and carrying the condenser, and, in fact, the whole mechanism of the interrupter, is a frame 17. A bolt 18 extends through frame 17 and plate 16. Pivoted on the frame 17, but insulated therefrom, is a lever 19 having one end 2O of non-conducting material. A coil spring 21 is confined between frame 17 and the end `of lever 19. The two ends of spring 21 are connected with the metal part of lever 19 and with the bolt 18,y The frame 17 and plate 16 are insulated from each other and frame 17 is insulated from bolt 18 and from spring 21. The other end of lever 19 carries a contact pin 22 which is normally pressed,

by spring 21, into contact with a pin 23 on the frame 17. The frame 17 and parts carried thereby are grounded. By intermittently moving lever 19 against the action of spring 21, the electric circuit is broken. lVhen spring 21 is allowed to actuate lever 19, the circuit is closed through the described elements 12, 11, 13, 11, 16, 18, 21, 19, 22, 23 and 17.

Cover 10 carries a bearing 25 for a worm 2G and a worm wheel or pinion 27. lVorm 26 is driven from one end of the rotor shaft and drives the pinion 27. The shaft of pinion Q7 carries a crank or eccentric 2S, which is positioned to operate a pin 29 engaging the end 2O of lever 19.

ln operation, the rotor shaft, through the worm 2li, pinion 27 and eccentric 28, intermittently advances the pin 29, thereby swinging lever 19 so as to separate the contacts Q2 and and break the circuit. In the further turning of the rotor shaft, eccentric 28 becomes so positioned as to allow pin 29 to retract and thus allow spring 21 to swing lever 19 into position to engage contact 22 with contact Q3, thereby closing the circuit.

There is nothing novel about the make and break device so far as it has been described. ln the known construction the frame 17 is rigidly positioned and it is ditlicult to adjust the device so as to secure the precise time intervals of circuit closing and circuit opening` which may be desired.

ln my improvement, the frame 17 is pivotally mounted at one end on a bracket 31 on cover 10, while the other end is sleeved on a pin secured te the cover 10. A coil spring 33 surrounds pin 3;. A nut 31, threaded on pin 32, engages the end ot' frame 17 sleeved on pin 32.

By adjusting nut 3a, so as to compress spring more or less, the frame 17 may be so positioned as to insure the engagement of its pin 23 with and throughout precisely half a revolution of the eccentric 28 or throughout any other predetermined fraction of a revolution of the eccentric 28, thereby enabling the make and break intervals to be accurately predetermined.

What l claim and desire to protect by Letters Patent is:

1. ln an electric switch, the combination or' a frame, a support on which one end of the trame is pivotally mounted, a lever pivoted between its ends on said frame, Contact pins near the pivoted end of the frame and on one end of the lever respectively a pump shaft and means operable thereby to intermittently positively swing the other end of said lever, in one direct-ion and thereby break contact between said pins, a spring adapted to swing the lever in the opposite direction when said lever is not so positively swung and thereby make contact between said pins, and means to adjust said frame on it-s support to predetermine the relative durations of closed and open circuits.

2. In an electric switch, the combination of a frame, a lever pivoted on said frame and adapted, when swung back and forth on its pivot, to open and close said circuit, a pump shaft and means operated therefrom to positively swing said lever in one direction, and a spring adapted to swing said lever in the opposite direction, of means to pivotally support said frame at one end, a pin on which such frame is sleeved at its other end, a spring coiled about said pin, and a nut threaded on the pin and adjustable to move the corresponding end of the frame against said spring.

In testimony of which invention, I have hereunto set my hand, at city of New York, New York, on this 16th day of June, 1931.

CYRUS HOlVARD HAPGOOD.

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